柳絮天涯
CH3COOH+NH3.H2O=CH3COONH4+H2O因为乙酸是弱酸,氨水是弱碱,它们在水中只能部分电离,所以溶液中离子浓度相对较小,而如果它们混合后就会发生反应生成乙酸铵,它是强电解质,在水中完全电离,所以可以使溶液中离子浓度升高,溶液导电能力逐渐增强.
室内设计--阿梅
country : a district outside of cities and towns; a rural area.village: a small group of dwellings in a rural area, usually ranking in size between a hamlet and a town. countryside: a rural region. so you can say: a village in countryside 我住在农村是不是必须用countryside呀? Using countryside is correct but you do not have to use countryside. You can also say I live in a village, or you can say I am from countryside. 至于说边远山区,我们用rural
欣欣向上,
1.village['vilid??]n.村庄, 乡村[集合词][the village]村民(动物的)群落village go out to the villages 下乡2.rural词性及解释 a. 乡下的, 田园的, 乡村风味的【法】 农村的, 乡村的, 有关农业的3.country['k??ntri]n.国家, 故乡田[旷]野乡村, 乡下国民, 民众(代表群众的)陪审团[只用单]地方, 地域(板球)外野(船内的)室, 间; 士官室in the western -tries 在西方各国city and country 城乡Which do you prefer to live in a city or in the country ? 你欢喜住在城里还是住在乡下?